*2.4.1 Capital conservation buffer and countercyclical buffer*

The case of Lehman Brothers and AIG call attention to how a single firm can boost up shock in the financial market as well as in the global economy. The financial crisis of 2007–2008 has revealed that microprudential guideline alone is not sufficient to address the systematic risk. Macroprudential regulation that takes into account the risk arising from interconnectedness of the financial institutions is important to respond to the systematic risk and financial stability in the economy.

Therefore, the macroprudential guidelines impose additional capital requirement for systematically important banks to reduce their default probability. BCBS advises building common equity of 2.5% of risk-weighted asset as capital conservation buffer so that in times of distress, this buffer can be scaled down to absorb losses. BCBS also advises the regulatory authorities to raise an additional countercyclical capital buffer of 2.5% to respond with excessive credit growth that may induce systematic risk in the financial sector. Banks incur a huge loss during downturn followed by a long excessive aggregate credit growth. After the asset price bubbles loans go unpaid, prices go down, banks loan decrease, and level of defaults even increases more [11]. To prevent this systematic risk, banks are advised to build additional capital up to 2.5% during the credit growth time that ensures the sufficient level of capital during the distress periods. It ensures that during the downturn, the banking institution has enough cushions to absorb the additional loss and provisioning. It also intends to support the financial stability by building countercyclical capital buffer during boom period through increasing to the cost of credit which reduces the demand for it [12].
